Why didn't Kuwait count for today's challenge (Bangladesh -> Yemen)? Is it calculated by the least countries inbetween, rather than shortest distance? If this is the case, I could see this making some weird paths, such as always going through Russia, if going West <-> East.
It's definitely just about number of countries. It's a reasonable choice for a game in isolation but also it would be a lot more complicated to find distances of a path that only passes through a list of countries (including convex countries, enclaves, etc).
By doing raw number of countries it only needs to know the abstract connectivity of countries for a classic path through a graph. It happens that under that metric Kuwait is never useful for a path since it only borders two countries which also border each other directly.
Similarily, getting from Delaware to Florida requires skipping South Carolina (on the usa puzzle). Now I know the rules. I've driven that route so many times but failed to get the optimum puzzle score.
Good concept and makes you have to think more precisely about borders I guess.